


Just a little key

by Deniera



Category: Final Fantasy XV
Genre: Awkward Sexual Situations, Birthday Smut, Kink Negotiation, Lingerie, M/M, Surprises
Language: English
Status: Completed
Published: 2017-04-03
Updated: 2017-04-03
Packaged: 2018-10-14 05:45:57
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,160
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10530147
Author URL: https://archiveofourown.org/users/Deniera/pseuds/Deniera
Summary: It's Gladio's birthday (shut up, it still is) and Prompto has put on something real special for his boyfriend. Trust me, he has.





	

**Author's Note:**

> I know I'm late but somewhere in this world it's still April 2nd, so bite me.  
> Happy birthday, Gladio!
> 
>    
> Not beta read.  
> 

 

 

 

“S-So.”

Gladio exhaled hard, mouth suddenly very dry, as he watched Prompto before him.

The blond was chewing on his lip, eyes down, a deep shade of red dusting his face and underlining his many freckles. His hair was without product for once, the longer strands softly grazing his cheek, and his naked legs were pressed together, one foot twisting around in the carpet of the bedroom.

Gladio’s eyes fixated on Prompto’s hands, clenched around grey, washed-out fabric pulled down to cover as much of his crotch and naked thighs as possible, and the tiny piece of fabric that was peeking out from under it at one side. Something dark, lace-y. Holy shit.

He was wearing one of Gladio’s old shirts (where’d he get that from anyway?), stretched out and revealing Prompto’s collar bones and parts of his shoulder around his neck, the logo too washed-out to recognise, and that alone was doing far more things to the tall man than it should. It was just a ragged piece of fabric, how was that possibly so sexy?

Maybe it was the prospect of what might be hidden beneath it.

“So?” he smiled at Prompto. “What’ve got here?”

At that he looked up at Gladio and gave him a small smile. He still seemed to be hesitating, but after inhaling deeply he pulled the hem of the shirt up a little to reveal a delicate piece of underwear, deep dark blue and lace all over, transparent at places and thick with pattern in others.

It was beautiful, a nice contrast to Prompto’s fair and freckled skin, and even the shirt, no matter how ragged, looked kind of nice with it. Gladio couldn’t help but smile and spread his arms out.

“C’mere,” he said, watching his boyfriend lovingly.

Prompto smiled and took a few steps until he stood right in front of Gladio, big hands coming to rest on his waist.

“You look beautiful.”

Blushing, Prompto averted his gaze, smile still on his lips. “Thank you,” he whispered, voice wavering.

Satisfied, Gladio pressed a soft kiss to his forehead. Usually Prompto was quick to dismiss compliments and never seemed to be able to take any of them seriously – thus Gladio was proud that this one was accepted to easily. It meant just again that Prompto trusted him, and he was particularly proud of that after he had put himself so openly on display with this underwear.

“Turn around for me a bit?”

Prompto swallowed and then slowly turned, Gladio’s hands still on his waist, just lightly enough that Prompto could move under him. His thumbs were grazing the top of the lace panties while he admired how the delicate fabric clung to the slender hips and firm cheeks.

Back to facing him Prompto received a long, sensual kiss.

“That is a very nice birthday gift,” Gladio smiled. He gave Prompto another once-over, eyes lingering at the bulge barely contained in the lingerie, and then realised that he was still fiddling, still seemingly nervous.

He looked back up, just seeing determination move into Prompto’s eyes.

“Uhm. Thank you.” He swallowed. “But, uh. That’s not your actual present. I just thought, uhm. It would, kinda, you know, go well with it?”

Gladio was puzzled when Prompto handed him a tiny silver key on a sky-blue ribbon. He twisted it in his hand, trying to figure out what it might be for. It was definitely far too small to be for a door lock, and it would neither fit any lock of significant size.

It struck him as the type of key for a padlock that would close a diary or a small jewellery box, like the ones Iris had owned when she was younger. He couldn’t really imagine Prompto using either of those items though.

“Okay. Uhm. Thank you, I guess? What’s it for?”

Prompto swallowed hard and seemed to grow an even deeper shade of red, head sinking lower until all Gladio could see was his blond hair and the back of his neck – not an unappealing sight.

“I... i-it’s. For this.” He slowly pulled the hem of the shirt farther up his abdomen so Gladio could see, and hooked the thumb of his other hand into the front of the panties, pulling them over his cock-

And Gladio choked, eyes growing large.

Prompto was flaming red at this point and completely silent, not even one muscle twitching. Usually Gladio would try to comfort him, but his head seemed to be devoid of any coherent thought.

Because Prompto was wearing a cage.

It was a delicate thing, transparent plastic surrounding the soft flesh with a wider, vertical opening at the front through which Gladio could see the rosy head of Prompto’s cock, and a thicker ring going all the way around the base of his dick and sac, closed shut with a small silver padlock - which belonged to the key Prompto had just given him.

He swallowed hard.

“How-,“ he rasped and then cleared his throat, reconsidering his question.  “You’re wearing this- for me?”

At this Prompto nodded, and lifted his head a little to peek at Gladio from under his eyelashes. “I, uhm.” He spoke quietly, voice soft. “You always... you always say I’m touching myself too much. I have no self-control.”

Gladio wanted to kick himself. “You know I’m just teas-!”

“I know,” Prompto interrupted. “I mean. I know. But... at the same time. You’re not _wrong_ , you know.”

A firm finger on his lips kept Gladio from protesting.

“I mean, uhm. I do touch myself a lot. ‘Specially when you’re not there. And. It kinda, has lost its appeal a bit? It’s become more of a mechanical thing I do. And... I thought, maybe this would be fun to try? So like... that my orgasms are just for you?”

He breathed in and out slowly. “So, how does that work? I take it off you when we’re gonna fuck?”

Prompto attempted to shake his head, but then stopped. “It depends. If that’s what you want?”

Eyebrows descending up into his hairline, Gladio blinked. “You mean there’s the option that you keep it on? While I fuck you?”

“Well. Yes. It’s supposed to make me shift my focus. Like, away from my dick and towards, uh... other places. Or, that’s one of the things you can wear it for. Uhm, it depends on the person, I guess.”

Gladio rubbed his eyes, shaking his head. “I- I’m sorry, I don’t understand. So, are you going to be in it for, what? How long can you even wear it? Isn’t that pretty gross over longer periods of time?”

Sighing, Prompto chewed his lip back in and averted his eyes. “It was a stupid idea, wasn’t it?” he asked quietly. “You can just- you can open it, and then we don’t have to speak of it again.”

Gladio just now realised that there was another ribbon, same colour as the one on his key, following the ring of the cage around Prompto’s genitals and looped in a pretty bow on top of the padlock.

“No!” He pushed Prompto’s hand away, which wanted to guide the key in Gladio’s hands back to the cage. “No, listen. It’s just, please explain it to me. I’m not appalled or anything, I just- I’ve never even heard of anyone doing anything like this. Please, could you- just tell me how you had imagined it? I want to understand what exactly you are offering.”

Not moving at first, the blond nodded after a while and slowly sat down on the bed, seemingly already forgotten that the panties were still tugged under his sac, putting his caged cock beautifully on display in his lap now that he was sitting.. The hem of the shirt had fallen down a little and rested softly around his waist. He was still holding it up a bit, his hand on the fabric apparently forgotten as well.

He looked up at him and Gladio was struck once again with how breathtaking his boyfriend was. _Pretty_ wasn’t usually a term he would apply to another man, but it fit Prompto so well that he couldn’t help himself. Sitting down next to him, he pressed an encouraging kiss to Prompto’s cheek, relief flooding through him at the shy smile he received in turn.

“So. Uh, to answer your questions. I can wear it as long as you’d want me to. I have a key as well, but I promise to just use it to open the cage for cleaning and nothing else, and I’d put it immediately back on when I’m done!”

“So... kind of a trust exercise?”

“Uh, yeah. Kind of. I made yours nice with the ribbon and all, and I thought it would be like, the main key? And I’d see mine as the maintenance key. So, the control is in your hands. And... we can explore along the way how we both like it?”

“Huh.” He thought about that. “As long as I’d want you to? What if I decided to make you wear it for months?”

Prompto shrugged, gobsmacking Gladio again. “It’s not... impossible or anything, you know. I did research on it before. I mean, I was thinking about starting it with you, so, you know, we could explore it together, but then again I thought it’d be nice to surprise you with it when I’m, like, a bit used to it already.”

He quirked his eyebrows again in curiosity. “You tell me this ain’t the first time you’re wearing it?”

Blushing, Prompto hesitatingly shook his head. “I... I was doing it on and off over the past few weeks. The first cage I got didn’t fit properly, and I wanted to train a bit too, so my body would be okay if you decided to have sex with me with it on.”

“Wait, what?” He squeezed his eyes shut again.” That your body would be okay? I could hurt you?”

“Ah, no! No, sorry, that’s not what I meant. I mean, maybe I meant it a little, getting hard in the thing is really uncomfortable, so I had to train a bit to keep my dick soft as well. But. What I actually meant was, uhm. That... that I would be able to come just from your cock.” Prompto was blushing furiously. Gladio understood though, the thought of his boyfriend coming untouched did exciting things to his body.

“That works?” he rasped.

Still blushed, Prompto cleared his throat and smiled at him shyly. “Not always. I’ve been trying a lot, but... I dunno what exactly triggers it. Sometimes it works and sometimes it doesn’t. I dunno. Uh, but it takes me a while to get there.”

Gladio stayed silent, just staring. He felt himself getting hot.

“So, big guy, what... what do you think?” Prompto was back to fiddling with the hem of Gladio’s shirt again, which had fallen down to his thighs while they had been talking. The lace panties and the cage were hidden by it as well, and Gladio realised he didn’t like that. He wanted to see it.

“I think,” he said while reaching for Prompto’s hands, pulling them out of his lap and towards his mouth, “that this is a very nice birthday present.” Pressing kisses to the freckled knuckles, he kept looking at Prompto, who was smiling brightly now.

“You like it?” Giddy was the right word. He was back to full energy, filling both Gladio and the whole room up with his excitement.

“I do. C’mon.” The next kiss was pressed to Prompto’s lips. “I wanna see if today is a ‘ _sometimes it_ _works_ ’. And then you tell me more about what exactly you did these last few weeks.”

Prompto beamed with happiness. “Deal!” With a sigh he leaned into the kiss and Gladio could feel him melt against him.

 

 

The sight was amazing, Gladio had to admit when Prompto sat in his lap, back to Gladio’s chest, grounding his hips onto his cock. They had never removed the bow from the cage and it bounced softly up and down with the plastic around Prompto’s soft, leaking flesh, trembling moans falling out of his mouth.

When Prompto actually seized up around him and came with long, white squirts through the opening of the cage, cum trickling weakly from his soft cock between both of their legs, Gladio stared with astonishment and came right there, hugging his shuddering boyfriend closer in his arms, groaning and whispering words of endearment and pride to him until they both started giggling.  

They needed a bit time to collect themselves, during which Gladio laid them down on the bed, carefully avoiding the mess Prompto had made on the sheets.

“Happy birthday, big guy,” was mumbled into his neck, and he couldn’t help but smile and think that Prompto had given him a very, _very_ nice gift, one that would hopefully bring both of them much joy and pleasure.

 

 

**Author's Note:**

> So, was this what you expected or did I manage to surprise you? :D
> 
> For the people who're wondering about the chastity device: [Ref](http://mainlyusedforwalking.tumblr.com/post/102547768998/ive-noticed-these-started-to-see-some-hits-what) (nsfw)


End file.
